[PATCH] Documentation: kernel-parameters.txt Add drm_kms_helper.poll

mika.kuoppala at intel.com mika.kuoppala at intel.com
Thu Oct 4 03:34:16 PDT 2012

From: Mika Kuoppala <mika.kuoppala at intel.com>

Add description for drm_kms_helper.poll module parameter introduced
by commit: e58f637bb96d5a0ae0919b9998b891d1ba7e47c9

Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
 Documentation/kernel-parameters.txt |   11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index f777fa9..ad97749 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -741,6 +741,17 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			if its name and a colon are prepended to the EDID
+	drm_kms_helper.poll=
+			Polling for connected VGA devices on older systems
+			can be quite expensive, causing latencies of
+			several hundred milliseconds. This will cause visible
+			stalls, for example in video playback. If you
+			experience stalls in display output occurring every
+			10 seconds (DRM_OUTPUT_POLL_PERIOD=(10*HZ)), disabling
+			polling might help.
+			Format: <bool>  (1/Y/y=enable, 0/N/n=disable)
+			default: enabled
 	dscc4.setup=	[NET]
 	dyndbg[="val"]		[KNL,DYNAMIC_DEBUG]

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